An Etymological Dictionary of the German Language/Annotated/Räude
Räude, feminine, from the equivalent Middle High German riude, rûde, feminine, Old High German rûda, feminine, ‘scab, mange, scabies,’ for an earlier *hrûda, since it is allied to Old Icelandic hruðr, masculine, ‘scab of a wound’; compare Dutch ruit, ‘scab, itch.’ —